A public switched telephone network (PSTN), cellular or mobile network, or Internetwork generally operate to support a large number of organizations and individuals who subscribe to the services offered by a network service provider. Among other things, such networks support protocols for connecting telephone calls, text messages (SMS) or electronic messages (SMTP) initiated by a source device to a destination device. At some point, marketing professionals discovered that they could inexpensively expose a large number of subscribers to their products or services by employing computer generated call/messaging applications. Unfortunately for the subscribers, most of the calls or messages they receive in this manner from these marketing professionals are unwanted and annoying, and so the subscribers typically employ methods to filter out these unwanted calls.
In the case of computer generated telephone calls or text messages, subscribers with answering machines or with caller ID can “screen” each call to determine whether or not to accept the call. In the case of unwanted electronic messages (so called junk mail), applications are available that allow a subscriber to apply differing degrees of filtering to incoming messages. Regardless of the method used to either screen or filter incoming calls or messages, it is incumbent upon the recipient of the unwanted call or message to take the time to manually examine the source of each call or message, or to listen to a recorded message, in order to determine whether or not they wish to accept or respond to a call.
One solution to the problem of manually screening/checking each telephone call is to apply an automatic call blocker to a telephone line that requires each caller to enter a code to complete their call. Since computer generated calls are not able to enter the requested code, these calls will be dropped and so the subscriber is not annoyed by these calls. Another solution to this problem is to compare caller identification information included in an incoming call with caller identification information stored on a telephone device, and allowing the call to be completed if there is a match or rejecting the call if there is not a match.